Technical Field
The present invention relates to semiconductor devices and, more particularly, to forming contacts and interconnects for semiconductor devices.
Description of the Related Art
Existing devices predominately use tungsten for the middle of line interconnects and contacts. However, as device dimensions continue to scale down to the 10 nm node and beyond, tungsten structures experience increasing resistance. This increased resistance is partly due to the thick liner materials needed for tungsten adhesion to underlying insulator layers and for the protection of oxides during the tungsten chemical vapor deposition process. These highly resistive liners (e.g., titanium/titanium nitride) occupy a large fraction of the total trench volume, which limits the actual amount of tungsten that may be deposited. A decreased conductor cross section results in an increased resistance for the conductor.